1. Field of the Invention
The present invention relates to a robot simulation system which simulates a takeout process by a robot for successively taking out bulk stacked workpieces.
2. Description of the Related Art
A robot simulation system is used for simulating a robot handling a workpiece or performing other predetermined operations in a virtual space. The results of simulation are utilized for evaluating the control program of the robot and for changing the program or the positional relationship of objects in the work space as necessary.
A known robot simulation system which simulates a takeout process for successively holding and conveying bulk stacked workpieces to a predetermined position by a robot. In the related art, the takeout process is simulated by, for example, arranging a three-dimensional model of a camera, which detects the positions and postures of the workpieces, in a virtual space.
JP2007-241857A discloses a robot simulation system which simulates off-line the operation of a robot which has a visual sensor. This robot simulation system is configured to identify a target workpiece model to be taken out and measure the position and posture of the target workpiece model, based on a two-dimensional virtual image which is obtained by a sensor model which captures an image of workpiece models in a virtual space.
JP2007-326160A discloses a robot simulation system which is configured to obtain a virtual image of a workpiece by a camera model which is arranged in a virtual space. In this robot simulation system, a teaching point for the robot model is corrected based on the obtained virtual image.
JP2013-101045A discloses a recognition system which is configured to recognize the position and posture of an object based on a two-dimensional image obtained by a camera and three-dimensional information which is obtained by a range sensor. This related art is intended to shorten the time which is required for processing the two-dimensional image by setting search conditions for detecting the two-dimensional position of the object based on the three-dimensional information.
JP2007-245283A discloses a workpiece posture detecting system which is provided with a camera for acquiring image data of a workpiece. This workpiece posture detecting system is configured to detect the posture of a workpiece based on a stable posture which best matches the posture of the workpiece in the image data which is obtained by the camera, among a plurality of stable postures of the workpiece which are stored in advance. This related art is intended to shorten the calculation time which is required for matching.
JP2009-128191A discloses an object recognition system which is configured to recognize the position and posture of an object by comparing three-dimensional surface shape data of the object to be recognized with three-dimensional surface shape data acquired by sampling actual state of the object which is obtained by a distance sensor, or the like.
JP2014-013146A discloses a three-dimensional measurement system which is provided with two cameras for capturing images of a workpiece at different viewing points and is configured to measure the three-dimensional position of the workpiece. This three-dimensional measurement system is designed to measure the three-dimensional position of the workpiece, based on a first image which is obtained by a first camera and a second image of a second camera which is cut out in accordance with a cutout range of the second camera which is calculated based on the first image.
In a takeout process of workpieces, a range sensor may be used to obtain three-dimensional information of workpieces. Therefore, there is a need for a robot simulation system which acquires three-dimensional information of bulk stacked workpieces in a virtual space by a range sensor, and thereby enables simulation of the takeout process.